JP2003293856A - Metallic gasket - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metallic gasket adaptable to enhanced performance of an internal combustion engine. <P>SOLUTION: The metallic gasket interposed between a cylinder block and a cylinder head to seal a space between both faces is composed of elastic metal base materials A<SB>1</SB>and A<SB>2</SB>having protruding beads 2 and 3 in circumferential rim parts of openings 1 for a cylinder, and an annular sheet metal B thinner than the base materials and arranged between the base materials so as to face the beads 2 and 3. It is composed so that a spring constant of the protruding bead of the base material A<SB>1</SB>in a cylinder block side is high, a spring constant of the protruding bead of the base material A<SB>2</SB>in a cylinder head side is low, and a bead attached to the elastic metal base material A<SB>2</SB>is not formed. By varying the spring constants of the beads 2 and 3, sealing performance is maintained, and sinking and deformation of the cylinder block and a deck face of the cylinder head is reduced. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a metal gasket interposed between a cylinder block and a cylinder head of an internal combustion engine.

[0002]

2. Description of the Related Art In an internal combustion engine, a sealing function is provided by interposing and tightening a metal gasket on a joint surface between a cylinder block and a cylinder head. recent years,
Rapid technological innovations such as downsizing and weight reduction and higher output of internal combustion engines have been carried out, and as a result, it has become possible to reduce the thickness of components such as cylinder heads and cylinder blocks, or to lower the rigidity by using aluminum materials. It tends to be achieved.

In the conventional metal gasket, in order to maintain a high surface pressure at the peripheral edge of the cylinder opening, elastic metal substrates having convex beads having a high spring constant are laminated, and a bead having a high spring constant is laminated. A means for exerting the function of the internal combustion engine is applied by sandwiching a thin metal plate in the region of the portion and taking a structure in which only the peripheral edge portion of the cylinder opening is thicker than the other portions.

[0004]

However, in recent years, the internal combustion engine has been made smaller and lighter, the space between the cylinder openings has become narrower, and the aluminum material has been used as a constituent member.
It tends to reduce the rigidity of the deck surface. Further, due to the vibration amplitude generated by the operation of the internal combustion engine, the increase in body expansion, etc., the flange surfaces of the cylinder head and the cylinder block are gradually depressed, and the width of the liner inserted in the cylinder peripheral portion is gradually narrowed. As a result, there is a tendency that the liner sinks and the bolt axial force decreases.

Further, in a structure in which a bead having a high spring constant is arranged at the peripheral edge of the cylinder opening to locally apply a high surface pressure to concentrate the load, the low strength flange surface of the component member is depressed or deformed. Is to be increased.

In order to solve the above problems, the present invention lowers the spring constant of the bead applied to the peripheral edge of the opening of the cylinder of the elastic metal substrate to a flange surface where the constituent member has low strength to prevent deformation and behavior. It is possible to provide a metal gasket capable of reducing the depression or deformation of the flange surface of the cylinder head and the cylinder block or the reduction of the bolt axial force while maintaining the sealing performance by increasing the height for a large flange surface. Has an aim.

[0007]

In order to achieve the above object, the present invention is a metal gasket which is interposed between a cylinder head and a cylinder block to seal between both surfaces and which seals a peripheral portion of an opening for a cylinder. The gist is to stack elastic metal substrates having different spring constants at different parts.

According to the above construction, the elastic metal substrate having the seal structure having a high spring constant is arranged on the cylinder block surface where the behavior of the flange surface or the subsidence of the sleeve occurs, and the cylinder head surface of the constituent member having low strength is arranged. By adopting a laminated structure in which an elastic metal substrate having a structure having a low spring constant is arranged, it is possible to cope with the behavior, deformation, and depression of the flange.

Further, the material of the elastic metal substrate arranged so as to be in contact with the cylinder head surface is made thinner than that of the elastic metal substrate in contact with the cylinder block surface, and the material hardness is avoided so as to cope with the depression or deformation of the cylinder head surface. To do so.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION As a preferred embodiment of the present invention, as shown in FIGS. 1 and 2, beads 2 and 3 having different spring constants are formed as a seal portion at the peripheral portion of a cylinder opening 1. An annular metal thin plate B thinner than the elastic metal substrate is sandwiched between the seal portions of the elastic metal substrates A ₁ and A ₂ .

The annular metal thin plates B are adjacent cylinders.
The metal thin plate B is configured so as to be integrally connected between the openings.
The locking portion 4 integrally projected from the outer peripheral edge of the elastic metal base
Board A ₁Put it in the slit 5 formed in the
Set. In addition, a thin metal plate thinner than the elastic metal substrate is used.
The area outside the bead formed on the peripheral edge of the cylinder opening
It is also possible to provide a thick secondary plate by folding back at.

[0012]

1 to 2 show a first embodiment of the present invention.
Fig. 1 is a plan view of a metal gasket, and Fig. 2 is its (XX).
It is a cross-sectional enlarged view of a line. Within the range shown in Table 1 below, the metal gasket is an elastic metal substrate A _{1 in} which the bead spring constant is increased by narrowing the width of the convex bead 2 formed along each cylinder opening 1 of the multi-cylinder engine. , The elastic metal substrate A whose spring constant is lowered by widening the width of the bead 3
₂ , the metal thin plate B, which is thinner than each elastic metal substrate, is sandwiched in the required region at the peripheral edge of the cylinder opening 1.

By making the plate thickness of the elastic metal substrate A ₂ thinner than the plate thickness of the elastic metal substrate A ₁ within the range shown in Table 1, the beads formed along the cylinder opening 1 of each elastic metal substrate are The structure is such that the spring characteristics can be changed. Further, a structure without a bead formed on the elastic metal substrate A ₂ is also included.

By setting the material hardness of the elastic metal substrate A ₂ to be lower than that of the elastic metal substrate A ₁ within the range shown in Table 1, the spring of the bead formed along the cylinder opening 1 of each elastic metal substrate. The structure is such that the characteristics can be changed.

[0015]

[Table 1]

The annular metal thin plate B is constructed so as to be integrally connected between the adjacent cylinder holes, and the annular metal thin plate B has a locking portion 4 integrally projected from the outer peripheral edge of the elastic metal substrate A _1. It is fixed by putting it in the slit 5 formed in the above and folding it back.

FIG. 3 shows a second embodiment of the present invention. In the present embodiment, the seal structure portion around the cylinder opening peripheral portion of the elastic metal substrate A ₂ is flattened, and the locking portion 4 of the thin metal plate B is fixed by inserting it into the slit 5 of the elastic metal substrate A ₁ and folding it back. In addition, the elastic metal substrates A ₁ and A ₂ sandwich the elastic metal substrates A ₁ and A ₂ .

FIG. 4 shows a third embodiment of the present invention. In this embodiment, the thin metal plate B is made of elastic metal substrates A ₁ , A.
Is a thick folded only convex bead 2 and 3 the seal portion of the opening edge for the _second cylinder, and is configured to spread the thin metal plate B to the bead area outside of the cylinder opening peripheral portion. According to this configuration, the surface pressure of the convex beads 2 and 3 can be increased, the surface pressure of the cylinder opening becomes uniform, and the bead is tightened by full compression to improve the fatigue resistance of the bead. Also, it is possible to suppress the reduction of the bead surface pressure.

In the first to third embodiments described above, the structure in which the peripheral edge of the cylinder opening of the elastic metal substrate is sealed is described. The same structure as described above can be applied to the peripheral edge seal.

[0020]

As described in detail above, according to the present invention,
The following effects are obtained. (1) By giving a seal structure having different spring characteristics to each elastic metal substrate, it gives an accurate sealing performance to the deck surface of different flange rigidity to be sealed, so that the flange to be sealed is deformed or depressed. Can be suppressed. (2) Further, the number of manufacturing steps can be reduced by reducing the bead molding portion.

[Brief description of drawings]

FIG. 1 is a plan view of a metal gasket showing a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view taken along line (XX) of FIG.

FIG. 3 shows a second embodiment of the present invention, which corresponds to (X
FIG. 7 is an enlarged cross-sectional view taken along line X-;

FIG. 4 shows a third embodiment of the present invention, which corresponds to (X
FIG. 7 is an enlarged cross-sectional view taken along line X-;

[Explanation of symbols]

A ₁ , A ₂ Elastic metal substrate B Metal thin plate 1 Cylinder opening 2, 3 Convex bead 4 Locking part 5 Slit

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hironobu Konaka             7-1-43, Nagatsuda, Midori-ku, Yokohama-shi, Kanagawa             Denia Park No. 201 (72) Inventor Takeshi Murata             1-4-Sugita Tsubo, Isogo-ku, Yokohama-shi, Kanagawa             203 F term (reference) 3J040 BA01 EA05 EA17 EA27 FA01                       HA08 HA17

Claims (6)

[Claims] 1. A metal gasket interposed between a cylinder head and a cylinder block to seal between both surfaces, wherein the elastic metal substrates have different spring constants at the seal portion at the peripheral edge of the cylinder opening. A metal gasket characterized by a structure in which a thinner metal plate is sandwiched only at the peripheral edge of the cylinder opening. 2. The metal gasket according to claim 1, wherein the elastic metal substrates that sandwich the thin metal plates are made of different materials. 3. The metal gasket according to claim 1, wherein the elastic metal substrates sandwiching the thin metal plates have different plate thicknesses. 4. The metal gasket according to claim 1, wherein a convex bead is formed on a peripheral edge portion of the cylinder opening of the elastic metal substrate, and a width and a height of a bead shape formed on each elastic metal substrate are different from each other. 5. The metal gasket according to claim 1, wherein the bead is formed only on one of the elastic metal substrates sandwiching the thin metal plate. 6. The metal gasket according to claim 1, wherein the thin metal plate is thickened by folding back only the cylinder opening peripheral portion of the elastic metal substrate.